I'm not sure if this belongs in product ideas, or the fabrication section.

MC move this to your discretion as you see fit.

I’m looking for a way to get more heat out of the heater box, while maintaining a 185 degree T-stat.

So here’s my idea, find a way to feed the heater box from the line coming out of the engine, instead of having it to be fed by the line going into the engine from the radiator.

Do you think the heater box could handle the extra temps, and BTW what kind of exit and entry water temps are we talking about, coming out of the engine?

Perhaps this could be as simple as tapping into the bottom line of the radiator, and matching this up with the supply line no the Heater Box.

Respectful comments appreciated:
Mike